Locomotion function is one of the important behavior parameters in animal research for human neurodegenerative diseases such as Parkinson's disease, Huntington's disease, and Alzheimer's disease. Neurodegenerative animal models have been well-established in rodents. Animal models with such diseases exhibit characteristic motoric deficits including declined movement activity, decreased movement speed, and reduced traveling distance. With an effective drug treatment, the animal locomotion function could be recovered to a great extent. Therefore, automated logging of the animal's locomotion function is essential in the pharmaceutical laboratory.
A number of inventors proposed methods to detect laboratory animal dynamic motion activity. The Stigmark et al U.S. Pat. No. 3,656,456 provides a system to monitor motion activity by detecting electrode capacity imbalance across a transformer bridge which results from animal movement in the environment. The Castaigne U.S. Pat. No. 3,540,413, the Vajnoszky U.S. Pat. No. 3,633,001 and the Meetze U.S. Pat. No. 3,974,798 disclose methods to detect laboratory animal motion activities by measuring the conductance of animals in contact with electrodes.
Methods of detecting laboratory animal locations are also provided by many other inventors. The earlier method disclosed by U.S. Pat. No. 3,304,911 (Hakata, et al) uses a pair of movable infrared light receivers to track animal locations in a square field. Salmons U.S. Pat. No. 3,439,358 utilizes multiple receiving antennae to detect animal location using the antennae's proximity to the animal. Other inventors report methods to detect animal location in a rectangular cage by employing infrared transmitter and receiver arrays; these inventors include Czekajewski, et al (U.S. Pat. No. 4,337,726), Mandalaywala, et al (U.S. Pat. No. 4,574,734), Matsuda (U.S. Pat. Nos. 5,608,209 and 5,717,202) and Young (U.S. Pat. No. 5,915,332). Sakano U.S. Pat. No. 4,968,974 also proposes an infrared position detection system for an animal in a cylindrical cage.
An advantage of the present invention is the provision of an inexpensive apparatus that can easily adapt to the conventional laboratory animal cage, the so-called animal home cage, without any special enclosures or modifications to the existing cage.